The present invention relates to a series of new silicon-containing compounds which may be considered as 3-(1,2,4-triazol-1-yl or imidazol-1-yl)-2-hydroxy-2-(optionally substituted phenyl)-1-(tri-substituted silyl)propane derivatives, and which have valuable anti-fungal activities, which may be applied in the agricultural, horticultural and medical fields. The invention also provides methods and compositions using these compounds as well as processes for their preparation.
A number of tri-substituted silyl derivatives in which a triazolyl group is separated from a silicon atom by a carbon chain is known and some are known to have fungicidal properties. For example GB Patent Specification No. 2 175 301 describes a number of compounds which are said to be primarily plant growth regulators, but which are also said to have fungicidal properties. These compounds include, among many others, some trialkylsilyl derivatives, of which the only specific example is given in Example 11 and is 3-t-butyl-3-hydroxy-4-(1,2,4-triazol-1-yl) 1-trimethyl-silyl 1-pentyne, which differs from the compounds of the present invention in that it possesses a t-butyl group in place of the optionally substituted phenyl group of the compounds of the present invention, in that it is an alkyne, rather than alkane, derivative and in that it has a longer aliphatic chain than do the compounds of the present invention.
GB Patent Specification No. 2 224 278 also describes a number of compounds which are said to be plant growth regulators or fungicides, and which include, among many others, some trialkylsilyl derivatives. The only compound of this type specifically disclosed appears in Example 4 of that GB Specification and is 3 (2,4. dichlorophenyl)-3-hydroxy-4-(1,2,4-triazol-1-yl) 1-tri-methylsilyl-1-butene, which differs from the compounds of the present invention in that its aliphatic chain, and generally the aliphatic chains of the compounds in the GB Specification, is a butene, rather than propane, chain, that is, it is longer and it is unsaturated.
The closest prior art, however, is thought to be that described by J-F. Chollet et al. [Pestic. Sci., 29, 427-435 (1990)], where the compound identified as XX (Table 1, page 431), which may be called 4-(4-chlorophenyl)-4-hydroxy-5-(1,2,4-triazol-1-yl)-3-trimethylsilyl-1-pen tene, differs from certain of the compounds of the present invention only in the presence of a vinyl substituent on the propane chain.
However, the prior art compounds, including those specifically described above, do not, in general, have sufficient activity. Moreover, one important property of compounds intended for use as agrochemical or pharmaceutical fungicides is that they should exhibit their activity at low dosages and should not induce any adverse side-effects. In addition, in the case of an agrochemical fungicide, it is a well recognized desideratum that the fungicide should have a systemic action, so that it may, for example, be applied as a coating to seeds or may be applied directly to crops or may be applied indirectly to submerged crops, such as to rice crops, and will be translocated throughout the plant.
Although each of the prior art compounds referred to above meets some of these requirements, none meets them all to a sufficient extent, and, in particular, most fail to exhibit any systemic activity at all, and, even in the one isomer of a prior art compound where some systemic activity is exhibited, this is lower than that of similar compounds of the present invention. As will be shown hereafter, the only compound included within the prior art to demonstrate any systemic activity is one isomer of 4-(4-chlorophenyl)-4-hydroxy-5-(1,2,4-triazol-1-yl)-3-trimethylsilyl-1-pen tene, which isomer was not, in fact, separated from another, and systemically inactive, isomer by the prior art.
We have now surprisingly discovered a series of 3-(1,2,4-triazol-1-yl or imidazol-1-yl)-2-hydroxy-2-(optionally substituted phenyl)-1-(tri-substituted silyl)propane derivatives which are believed to have these desirable properties. This is the more surprising in that Chollet et al. suggest that unsaturated compounds, especially allylic compounds, are the most active, whereas the compounds of the present invention do not contain an unsaturated aliphatic group.